Java 9 Programming By Example

Overused locks

In many situations, it may happen that the threads are waiting on a lock, which protects a resource from concurrent access. If the resource cannot be used by multiple threads simultaneously, and there are more threads than can be served, then the threads are starving. However, in many cases, the resource can be organized in a way so that the threads can get access to some of the services that the resource provides, and the locking structure can be less restrictive. In that case, the lock is overused and the situation can be mended without allocating more resource for the threads. It may be possible to use several locks that control the access to the different functionality of the resource.